Solvation rearrangement brings stable zinc/graphite batteries closer to commercial grid storage

September 10, 2020

With grid-scale renewable energy on the rise, many scholars have shifted their attention from energy generation to energy storage. Whether it is solar cells converting sunlight into power, or windmills transforming air currents into electrical currents, the sources of renewable energy generation are inherently variable.

Exceptionally cloudy or still days can cause noticeable fluctuations in the power output of renewable sources. A major hurdle for grid-scale renewable energy is how to efficiently store these often intermittent energy sources for later, more evenly distributed uses.

A research team led by Prof. CUI Guanglei and ZHAO Jingwen from Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences (CAS) is one step closer to solving this storage problem.

The team has focused on Zinc anode and Graphite cathode based Dual-ion batteries (DIBs) due to their low cost and high-voltage capabilities, making them a great candidate for large, grid-scale storage devices. Their findings were published in Angewandte Chemie International Edition on August 18.

In these batteries, Zn deposition occurs on a Zn anode during charging process while negatively charged anions weave themselves into the Graphite cathode allowing energy storage for later use, a process known as intercalation. Zinc/Graphite batteries, however, do have a catch.

"Unfortunately, anions often used for graphite intercalation reactions could complex with carbonate in the electrolyte. This decreases the oxidation stability of carbonate and prevents the development of DIBs with high efficiency, low self-discharge and long shelf/cycling life," says CUI.

Essentially, the electrolytes used to transfer charge through the battery would undergo oxidative decomposition at high voltage regions, lowering the efficiency and the lifetime of the battery. This is an essential problem to solve before applying this type of battery to large scale power storage.

The group's approach enhanced the oxidation stability of carbonate-based electrolytes through tuning the anion solvation structure. By introducing a strongly-electron donating trimethyl phosphate (TMP) solvent, the team was able to trap the anions in the TMP solvation regime and decouple the anions from carbonate solvent.

Consequently, the operating voltage of the Zinc/Graphite batteries was raised by 0.45 V while also enabling a long-life cycle (92% capacity retention after 1000 cycles). This could not only extend the cycle life of Zinc/Graphite batteries, but also increase the capacity of anion intercalation into graphite. The authors emphasized that "a deep understanding and regulation of the anion solvation structure is essential."

"Here, we regain the anti-oxidative nature of carbonate-based electrolytes to support high-voltage Zinc/Graphite cells, by reorganizing the intermolecular, i.e., ion-solvent and ion-ion, interactions," CUI said.

Their future work will be focused on increasing the energy density, suppressing the self-discharge behavior as well as lowering the cost of the electrolyte for Zinc/Graphite batteries. The ultimate goal is to commercialize the Zinc/Graphite battery in grid-scale energy storage.
-end-


Chinese Academy of Sciences Headquarters

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.